Uranium nitride compounds are important molecular analogues of uranium nitrides materials such as UN and UN2 which are effective catalysts in the Haber-Bosch synthesis of ammonia, but the synthesis of...

The chemistry of lanthanides is limited to one electron transfer reactions due to the difficulty of accessing multiple oxidation states. Here we report that a redox-active ligand combining three siloxides...

Thorium redox chemistry is extremely scarce due to the high stability of ThIV. Here we report two unique examples of thorium arenide complexes prepared by reduction of a ThIV‐siloxide complex in presence of naphthalene, the mononuclear arenide complex [K(OSi(OtBu)3)3Th(η6‐C10H8)] (1) and the inverse‐sandwich complex [K(OSi(OtBu)3)3Th]2(μ‐η6,η6‐C10H8)] (2). The electrons stored in these complexes allow the reduction of a broad range of substrates (N2O, AdN3, CO2, HBBN). Higher reactivity was found for the complex 1 which reacts with the diazoolefin IDipp=CN2 to yield the unexpected ThIV amidoalkynyl complex 5 via a terminal N‐heterocyclic vinylidene intermediate. This work showed that arenides can act as convenient redox‐active ligands for implementing thorium‐ligand cooperative multielectron transfer and that the reactivity can be tuned by the arenide binding mode.

Thorium nitrides are likely intermediates in the reported cleavage and functionalization of dinitrogen by molecular thorium complexes and are attractive compounds for the study of multiple bond formation in felement chemistry, but only one example of thorium nitride isolable from solution was reported. Here, we show that stable multimetallic azide/nitride thorium complexes can be generated by reduction of thorium azide precursorsa route that has failed so far to produce Th nitrides. Once isolated, the thorium azide/nitride clusters, M 3 ThNTh (M = K or Cs), are stable in solutions probably due to the presence of alkali ions capping the nitride, but their synthesis requires a careful control of the reaction conditions (solvent, temperature, nature of precursor, and alkali ion). The nature of the cation plays an important role in generating a nitride product and results in large structural differences with a bent ThNTh moiety found in the Kbound nitride as a result of a strong K−nitride interaction and a linear arrangement in the Cs-bound nitride. Reactivity studies demonstrated the ability of Th nitrides to cleave CO in ambient conditions yielding CN − .

We have prepared NHC‐CuI complexes with a rotaxane structure and used them as sterically sensitive catalysts for one‐pot sequential copper‐catalyzed azide/alkyne cycloadditions in solutions containing all of the coupling partners premixed in unprotected form. Most notably, a photolabile and sterically encumbered complex first catalyzed the coupling of a less bulky azide/alkyne pair; after removing the protective macrocyclic component from the rotaxane structure, through irradiation with light, the exposed dumbbell‐shaped NHC‐CuI complex catalyzed the second click reaction of a bulkier azide/alkyne pair. Using this approach, we obtained predominantly, from a single sealed pot, a bis‐triazole product (84 %) from a mixture of two sterically distinct azides and a diyne.

Thorium redox chemistry is extremely scarce due to the high stability of Th IV . Here we report two unique examples of thorium arenide complexes prepared by reduction of a Th IV -siloxide complex in presence of naphthalene, the mononuclear arenide complex [K(OSi(O t Bu) 3 ) 3 Th(η 6 -C 10 H 8 )] ( 1) and the inverse-sandwich complex [K(OSi(O t Bu) 3 ) 3 Th] 2 (μ-η 6 ,η 6 -C 10 H 8 )] (2). The electrons stored in these complexes allow the reduction of a broad range of substrates (N 2 O, AdN 3 , CO 2 , HBBN). Higher reactivity was found for the complex 1 which reacts with the diazoolefin IDipp = CN 2 to yield the unexpected Th IV amidoalkynyl complex 5 via a terminal N-heterocyclic vinylidene intermediate. This work showed that arenides can act as convenient redox-active ligands for implementing thorium-ligand cooperative multielectron transfer and that the reactivity can be tuned by the arenide binding mode.

We have prepared NHC‐CuI complexes with a rotaxane structure and used them as sterically sensitive catalysts for one‐pot sequential copper‐catalyzed azide/alkyne cycloadditions in solutions containing all of the coupling partners premixed in unprotected form. Most notably, a photolabile and sterically encumbered complex first catalyzed the coupling of a less bulky azide/alkyne pair; after removing the protective macrocyclic component from the rotaxane structure, through irradiation with light, the exposed dumbbell‐shaped NHC‐CuI complex catalyzed the second click reaction of a bulkier azide/alkyne pair. Using this approach, we obtained predominantly, from a single sealed pot, a bis‐triazole product (84 %) from a mixture of two sterically distinct azides and a diyne.

[2]Rotaxanes displaying one‐off photo‐triggerable gelation properties have been synthesized through the “clipping” of photo‐degradable macrocycles around the amide or urea functionalities of organo‐ and hydrogelators. Irradiation with UV‐light cleaved the photo‐labile macrocyclic components from the [2]rotaxanes, resulting in the free gelators being released into solution and, thereafter, forming gels. When the rate of gelation was sufficiently rapid, selective gelation of specific regions of the solution—and, indeed, photo‐patterning of the solution—was possible.